Machine having an improved take-up reel for winding hollow filaments

ABSTRACT

There is disclosed herein an apparatus and method for preparing a continuous, hollow, and semipermeable filament for use in a dialyzer which includes a plurality of substantially-equal-length open-ended fibers. 
     The apparatus includes a body having a supply spool of filament and a take-up reel having at least two radially-spaced support means about which the filament is wound. Drive means rotate the take-up reel and a filament guide is provided for laterally positioning the filament on the support member so as to prevent close packing of the filament windings. The take-up reel includes a winding plate for carrying the filament support means and hub-and-locking means for releasably mounting the winding plate on the machine. 
     The method includes winding the filament from the spool onto the take-up reel; grasping each of the sections of filament between the support means; and cutting the filament adjacent the support means so as to form a plurality of bundles of open-ended fibers for use in a hollow fiber dialyzer.

BACKGROUND OF THE INVENTION

This invention relates to a machine used in the manufacture of hollowfiber dialyzers of the type used in artificial kidney systems.

Artificial kidney systems include dialyzers or membrane diffusiondevices through which blood from a patient flows for treatment. One typeof dialyzer is known as a hollow-fiber dialyzer.

A hollow-fiber dialyzer includes an elongated, andgenerally-cylindrically-shaped casing within which many very-fine,hollow and semipermeable fibers are positioned and secured adjacenttheir terminal ends to the casing. Blood from the patient flows throughthe dialyzer inside the fibers. Dialysis solution flows through thedialyzer and surrounds and contacts the fibers so as to receive bodilywaste products from the blood and remove them from the dialyzer.

The fibers are made from a long hollow filament of cellophane or of acellulose derivative, such as sold under the trade name Cuprophan. Thefilament is continuous and is supplied on a spool.

In manufacturing the dialyzer it is impractical to individually cut thefilament into individual fibers, group or bunch the fibers, and thenassemble the dialyzer. One suggested process for bunching the fibers isto form the filament into a hank by winding the filament on a wheel,grasping the wound filaments at two points and removing the hank fromthe wheel. The hank is then pulled into a cylindrical casing. In thisform the filament is still continuous and after further preparation thelooped ends of the hank are cut so as to form the openended fibers. Ascan be appreciated, only one device can be made from each hank.

It is therefore an object of this invention to provide a method andapparatus for use in preparing the fiber bundles which is suitable foruse in the mass production of hollow fiber dialyzers.

In other winding systems the filament is wound on a support whichsupport ultimately becomes part of the device. Unfortunately, in thedialyzer the support is an inactive element which occupies space andthereby reduces the efficiency of the device.

It is thus another object to provide a winding machine wherein thewinding support does not become a part of the dialyzer.

This and other objects of this invention will become apparent from thefollowing description and appended claims.

SUMMARY OF THE INVENTION

There is provided by virtue of this invention method and apparatus forwinding a filament so as to prepare a plurality of fiber bundles for usein manufacturing hollow fiber dialyzers.

The machine includes: a base; at least one supply spool of continuousfilament; and a take-up reel having a plurality of radially-spacedsupports about which the filament is wound and between which thefilament can be bundled. A movable filament guide is provided which ispositioned between the supply spool and take-up reel for continuouslycontrolling the lateral positioning of the filament in a manner such asto assure a loose winding of the filament so that an upper winding ofthe filament crosses over a lower winding. This loose packing andcrossover assures effective flow of dialysis solution within thedialyzer and maximizes the efficiency thereof. The guide moves oroscillates in a lateral or axial direction with respect to the take-upreel and at a rate related to the rotation of the take-up reel so as toassure proper crossover.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one side of the winding machine showingthe take-up reel, two filament supply spools and the filament guide;

FIG. 2 is a diagrammatic and perspective view of a drive system fordriving the take-up reel and for moving the filament guide;

FIG. 3 is a perspective view, partially in section, showing a two-camsystem for controlling the movement of the filament guides on each sideof the machine;

FIG. 3A shows an alternative single cam system for controlling theguides;

FIG. 4 is an enlarged perspective view showing a filament guideassembly;

FIG. 5 is a side elevational view showing the take-up reel;

FIG. 6 is a sectional view taken substantially along line 6--6 of FIG. 5and showing a hub-and-locking mechanism for the take-up reel;

FIG. 7 is a greatly enlarged elevational view showing a portion of thetake-up reel;

FIG. 8 is a view taken substantially along line 8--8 of FIG. 7 andshowing the filament crossover;

FIG. 9 is a perspective view showing a split sleeve for use in bundlingthe filament for cutting into the fibers; and

FIG. 10 is an end view of the split sleeve with one side opened.

DESCRIPTION OF THE PREFERRED EMBODIMENT General

Referring now to FIG. 1, the winding machine 10 includes a body 12 oneach side of which is provided a winding mechanism. The body includes aboxlike main section 14, which is supported by a pair of legs 16 and 18.A control console and supply spool mounting section 20 is supported in acantilever fashion from the back end of the main body section 14.

Two substantially identical winding mechanisms are provided, one on eachside of the body. Thus, two winding operations can be performedsimultaneously, if desired.

Each winding mechanism includes upper and lower spool support shafts 22and 24, which extend laterally from the mounting section 20. Twofilament supply spools 26 and 28, each having wound thereon a continuoushollow filament, are mounted on the shafts 22 and 24. The filaments 30and 32 extend from the spools through the filament guide assembly 34 andto the driven take-up reel assembly 36. A protective and transparentcase, such as 38, having two access doors 38a and 38b is carried by themain body section so as to enclose the guide assembly and take-up reel.

Drive System

The rotation of the take-up reel assembly 36 and movement of thefilament guide assembly 34 are controlled by a drive system, which isenclosed with the main body section 14. The system includes an electricmotor 40, which drives both the reel assembly and the guide assembly.The motor speed can be varied between 0-2000 rpm.

The Reel Drive

The motor 40 is connected to the take-up reel through a gear and timingbelt system as described hereinafter. The motor 40 is connected to a5:1, worm-gear-type speed reducer 42 having an output gear 44. A gearedoutput drive timing belt 46 is trained about the gear 44, as well as thedriven gear 48, which is mounted on the cross-shaft 50. A counter,take-off gear 52 is mounted on the cross-shaft 50 and is connected to arpm counter 54 by a counter timing belt 56. The gearing system isarranged such that the counter is synchronized with the take-up reelassembly so as to indicate the take-up reel rpm.

A reel drive gear 58 is also mounted to the shaft 50 and is connected toa reel drive shaft 60 by a gear 62 on the shaft 60 and a timing belt 64.The take-up reel assembly 36 is mounted to an end of the shaft 60. Thusthe take-up reel is driven: by the motor 40; through the gear reducer42; through the gear 44, belt 46 and gear 48; through shaft 50; throughgear 58, belt 64 and gear 62; and through shaft 60. Through this systemthe take-up reel can be driven at between 0-400 rpm.

The Guide Drive

The guide assembly 34 is mounted so as to cause the filament toreciprocate or move laterally with respect to the take-up reel assembly36 at a rate related to the rotation of the take-up reel. The motor 40drives the guide assembly. A variable speed control 63 is mounted to themotor 40. The speed control includes a manual speed adjuster 65 and anoutput gear 66. The speed of the output gear 66 is controllable between0-400 rpm. A drive timing belt 68 is trained about the output gear 66and a smaller driven gear 70. For each revolution of the output gear 66,the driven gear 70 revolves 2.25 times, so as to provide a 2.25:1 gearratio. The driven gear 70 is secured to one end of a shaft 72, whichenters a gear box 74. A second aligned shaft 76 exits the gear box and agear 78 is secured to the outer end of the shaft 76. A rotatable camdrive shaft 80 extends upwardly from the gear box and is driven by theshaft 72. A bevel gear arrangement (not shown) is provided within thegear box for driving the shafts 76 and 80.

Another timing belt 82 is trained about the gear 78 and a gear 84 fordriving a second rotatable cam drive shaft 86 and a counter 88, througha gear box arrangement 89, which is similar to that previously describedin connection with the gear box 74. The counter 88 is synchronized withthe rotation of the shafts 80 and 86, which, in turn, is related to therate of reciprocation of the guide arm, so that the counter indicatesthe rate of guide arm reciprocation or oscillation.

Referring now to FIG. 3, each of the shafts 80 and 86 carry at theirupper end a cam, such as 90 and 92, which controls the reciprocation ofthe guide assembly 34 and the filaments. A reciprocating control rod 94extends from within the body 14 through a sidewall 14a and connects atits outer end to the guide assembly 34. At the inner end, the rod 94includes a cam follower 96, which is biased against the cam 90 by acoiled compression spring 98 that bears against a bearing plate 100 andthe cam follower 96. Rotation of the cam 90 causes the rod 94 toreciprocate. It will be appreciated that the guide arm on the other sideof the machine (not shown) is controlled in a similar manner.

With this arrangement the rate of reciprocation of the guide arm can becontrolled between 0-900 oscillations per minute.

In the alternative cam construction shown in FIG. 3A, there is a singlegrooved cam 103. Here there is only one drive shaft 80a which drives thesingle cam, which, in turn, controls the two control rods 93a and 94a.

It will be appreciated that the speed of the cam drive shaft 80 relativeto the take-up reel drive shaft 60 can be controlled and adjusted withthe speed control adjuster 65. If no adjustment is made, the ratio ofguide arm reciprocation to take-up reel rotation remains constantregardless of the speed of the take-up reel. However, use of theadjuster 65 permits adjustment and control of the ratio of guide armreciprocation to take-up reel rotation.

Guide Arm Assembly

The guide arm assembly 34 is mounted to the outside of sidewall 14a by avertically adjustable mounting plate 101, a pivotally adjustable sideplate 102 and a forwardly and rearwardly adjustable lateral supportplate 104. An upper filament sensing switch 106 is mounted to the topside of the plate 104 and a lower filament sensing switch 108 issupported by and is positioned below the plate 104. Each switch includesleaf-like member, such as 110, which is biased toward the filament andwhich engages and senses the presence of the filament, such as 30. Inthe event the filament breaks during winding, the member 110 movesupwardly and actuates means (not shown) for disabling the drive systemand for applying a controlled braking action to the supply spool shaftsand the take-up reel to minimize breakage of filaments on other reels.

An elongated and swingable guide arm 112 is pivotally mounted at itsback end to the support plate 104, forwardly of the switch 106, by a pin114. The control rod 94 is connected to the arm at a point intermediatethe ends of the arm by a universal-type joint 116. The head 112a at theforward end of the guide arm carries upper and lower spring-likefilament guides, such as 118, which cooperates with the spring-likefilament guides, such as 119, associated with the switches. As thecontrol rod reciprocates, the head 112a swings back and forth in amanner controlled by the cam 90.

The Take-Up Reel Assembly

The take-up reel assembly 36, as shown in FIGS. 5 and 6, includes afilament winding plate 120 and a hub-and-locking system 122 forremovably securing the plate to the machine.

The Winding Plate

The plate 120 has a large, circular and centrally positioned openingwhich defines the inner edge 124, and has six support edge carryingsections 126, 128, 130, 132, 134 and 135. Each of the sections arepositioned radially outwardly from the center of the plate and equallyabout the periphery.

A V-shaped filament support assembly, such as 136, is mounted on theplate at each of the support sections, such as 126. Each of the supportassemblies, such as 136, includes a pair of outwardly extending U-shapedfilament supports 138 and 140, each of which terminates in a lowerbeveled edge, such as 138a and 140a. Each of the supports, such as 138and 140, is bolted to the plate through bolt-receiving apertures in theplate 120. As can be seen in FIG. 5, the filament support assemblies canbe movably positioned in one of three different radial positions. Thusthe supports 138 and 140 can be moved from the inner position as shownto an intermediate position at 142 and 144, or to an outer position at146 and 148.

It will be appreciated that such changes in position can increase ordecrease the length of the filament bundles between the sets ofsupports. For example, by moving the supports radially outwardly, thelength of the bundles between the adjacent supports is lengthened. Thispermits the manufacture of hollow fiber dialyzers of different lengths.

The Hub-and-Locking System

The system 122 for securing the plate 120 to the machine is shown inboth FIGS. 5 and 6. That system includes a hub assembly 150, which issecured to an end of the winding shaft 60 by a set screw 151. The hubassembly includes a flanged, boss-like member 152 to which a wheel-likesupport plate 154 is secured. The support plate includes three radialspokes 156, 158 and 160, each of which has an elongated guide slot, suchas 162. The outer periphery of the support plate is L-shaped in sectionand defines an axial or laterally-extending shoulder 164 and acircumferential shoulder 166.

The take-up reel winding plate 120 is constructed such that the inneredge 124 can be fitted onto the shoulder 164 with the plate 120 againstthe circumferential shoulder 166. This fit prevents radial movement ofthe winding plate 120 relative to the hub 150. The plate 120 isremovably secured in driving relation to the hub assembly by six studs,such as 167a, which extend outwardly from the shoulder 166 and whichengage six stud-receiving apertures, such as 167b, in the winding plate.

Three generally radially-extending locking arms 168, 170 and 172 areprovided to secure the winding plate 120 to the support plate 154 bypreventing axial movement of the winding plate with respect to thesupport plate shoulder 166. The arms are secured at their inner ends tothe hub 150 by a pin, such as 174, and a pivotable collar-like member176. Each arm carries a guide block, such as 178, which moves radiallywithin the slot 162 in the arm. The guide block 178 is secured to thearm and in the slot by a pin 180. Each of the locking arms is of alength such that when the arms are in the extended, radial and lockingposition, the outer end of the arm is positioned radially outwardly overthe shoulder 164 and in overlying relationship to the plate 120. Withthis construction the arm can lock and hold the winding plate 120 on thewinding machine in fixed relation to the shaft 60.

The collar 176 is rotatable with respect to the shaft 60 and to thesupport arms, such as 160. As can be seen in FIG. 5, a stop pin 182defines the limits of movement for the collar 176. The collar is held inthe locked position by a spring-loaded detent assembly (not shown). Inthe position shown in FIG. 5, in full line, the arms are positioned tolock the plate in position. Rotation of the collar 176 causes the armsto retract and the guide members, such as 178, slide within the slots162, until the outer ends of the arms move within the inner edge of theshoulder 164. With the locking arms retracted, the winding plate 120 canbe removed from the machine by pulling it axially outwardly.

Operation of the Winding Machine

As can be seen from the drawings, the two spools of hollow-fiberfilaments are mounted on the shafts 22 and 24 and each filament isguided through the guide assembly 34 and started on the take-up reel 36.The machine is actuated so that the motor rotates the take-up reelassembly 36. As this occurs, the take-up reel draws filament from thesupply reel through the guide assembly. The action of the cams, such as90, causes the guide arm 112 to oscillate or move laterally, inwardlyand outwardly as the take-up reel rotates. The cam is designed in amanner such as to provide an even distribution of the filament on theguides. The shape of the cam cooperates in preventing build-up offilament at the edges of the guide by increasing the arm speed at eachend of the oscillation. Furthermore, the cam prevents close-packing ofthe filament windings and causes the filament which is being wound tocrossover the previous winding of the filament. This crossover isdiagrammatically shown in FIG. 8 where it can be seen that an upperfilament winding 190 crosses over a lower filament winding 192.

It has also been found that the use of the two reels is beneficial fromthe point of view that a sufficient quantity of filament is supplied soas to continuously feed the take-up reel and thereby avoid the need tostop the winding operation and start a second spool. This stopping hasbeen found to be detrimental to the efficiency of the dialyzer sinceundesirably large flow channels may be formed where on spool ended andthe other began. It is believed that the channel may be formed as aresult of differences in filament tension at the end of the first spooland at the beginning of the second spool.

During winding it has been found to be desirable to rotate the take-upreel at a speed greater than the speed at which the guide armoscillates. In one particular operation the take-up reel is driven at200 rpm and the guide arm is oscillated at 160 oscillations per minute.

It will be appreciated that as the geometry of the take-up reel, forexample the size and diameter of the take-up reel, changes that theoscillations of the guide arm must also change in order to effectuateproper crossover.

Once the filaments are wound on the take-up reel and the bundles are ofa sufficient size for use in hollow fiber dialyzers, the windingoperation is stopped.

Preparation of Fiber Bundles

An elongated split case 200 as shown in FIG. 9 is used in forming thefiber bundles from the filaments and for removing the bundles from thetake-up reel. The split case includes an upper semi-cylindrical member202 and a lower cylindrical member 204, which are joined by a pair offlexible hinges 206 and 208. As can be seen in FIG. 10, the sections canbe opened and positioned and clamped about the wound bundles of thefilament.

Referring now to FIG. 7, once the members are in position, they tightlygrasp the bundles of filament therebetween and the filament may then becut at either end of the case so as to form open-ended fibers and permitremoval of the bundles from the reel. The cutting converts thecontinuous filament to the individual hollow fibers used in thedialyzer. After cutting and removal, the individual bundles are thentreated and formed into the hollow fiber dialyzers.

It will be appreciated that numerous changes and modifications can bemade in the embodiments disclosed herein without departing from thespirit and scope of this invention.

What is claimed is:
 1. A machine for preparing a continuous, hollow, andsemipermeable filament for use in a hollow fiber dialyzer, whichdialyzer includes a plurality of substantially-equal-length openendedfibers formed from said filament, said machine including:(a) a body;atleast one supply spool of said filament, said spool being rotatablymounted on said body; (b) a take-up reel having at least two radiallyspaced support means about which said filament is wound, said reel beingrotatably mounted on said body; and (c) drive means for rotating saidtake-up reel; wherein the improvement comprises said take-up reel,including: (d) a hub member having locking means drivingly associatedwith said drive means; (e) winding plate means for carrying saidfilament support means being adapted for releasable securement indriving relation to said hub member; and (f) said support meanscooperating with said winding plate means for supporting said bundles ina substantially exposed disposition to facilitate cutting of saidbundles upon completion of winding on said take-up reel.
 2. A machinefor preparing a continuous, hollow, and semipermeable filament for usein a hollow fiber dialyzer, which dialyzer includes a plurality ofsubstantially-equal-length open-ended fibers formed from said filament,said machine including:(a) a body;at least one supply spool of saidfilament, said spool being rotatably mounted on said body; (b) a take-upreel having at least two radially spaced support means about which saidfilament is wound, said reel being rotatably mounted on said body; and(c) drive means for rotating said take-up reel; wherein the improvementcomprises said take-up reel, including: (d) a hub member having lockingmeans drivingly associated with said drive means; and (e) winding platemeans for carrying said filament support means being adapted forreleasable securement in driving relation to said hub member; (f) saidsupport means being constructed to receive said filament and group offilaments between adjacent support means into a single bundle, saidsupport means further being radially movable so as to permit adjustmentof the length of the filament bundle between adjacent support means; and(g) said hub member including radial slots dimensioned to receive guidemembers for relative radial movement therein, said locking meansincluding locking arms secured to said guide blocks for reversablymoving said locking arms from a retracted position to an extendedposition to lock said winding plate means onto said hub member.
 3. Themachine according to claim 1 wherein said winding plate includes alarge, central-mounting aperture; said hub member includes a peripheralshoulder means for mating cooperation with said mounting aperture; andsaid locking means includes central, pivotal-collar means associatedwith said arm means for moving said arm means between the retracted andthe extended position.
 4. The machine according to claim 3 wherein saidlocking means includes:(a) said locking arm being pivotably secured atone end to said guide member and pivotably secured at said other end tosaid pivotal collar means at a position displaced from the axis of saidcollar means such that rotation of said collar means causes said lockingarm to move radially as defined by the path of said slots in saidtake-up reel and to be displaced about the axis of said collar means toeffect moving of the locking arm between extended position to theretracted position.
 5. The machine according to claim 4 wherein saidwinding plate means is releasably secured to said hub member to preventrelative rotational movement.